Bass made his major league debut on June 13, 2011,[4] pitching a five-inning start and earning his first major league win. He was optioned back to San Antonio the next day, but was recalled again in late June.[5] Bass stayed with the big league club for the remainder of the year, pitching out of the bullpen until making two more starts in late September. He finished 2011 with a 1.68 ERA in 481⁄3 innings and 24 strike-outs versus 21 walks.

Bass with the Padres (2011)

Bass started 2012 in the Padres bullpen, but was added to the starting rotation on April 12 when Dustin Moseley injured his shoulder.[6] Bass made 14 starts for the club until he went on the disabled list in June with shoulder inflammation.[7] He rejoined the club in September, working out of the bullpen after making three rehab starts with Tucson. Bass finished 2012 with a 2-8 record and a 4.73 ERA in 97 innings, with 80 strike-outs against 39 walks.

On December 11, 2013, Bass, along with a player to be named later or cash considerations, was traded to the Houston Astros for a player to be named later or cash considerations.[8] The Astros sent Patrick Schuster to the Padres the next day.[9] Bass spent the 2014 season split between the Astros and the team's Class AAA affiliate, the Oklahoma City RedHawks. He appeared in 21 major league games and earned two saves. He was outrighted off the Astros roster on November 20, 2014.[10] On December 6th, Bass elected free agency.

He throws four pitches: a four-seam fastball (90–95 mph), a slider (83–87), a cutter (85–87)and a changeup (82–86). Bass throws all three pitches to right-handers and left-handers, but he uses the slider more against right-handed batters and the changeup more against lefties. He favors the slider with two strikes.[12]